Purification of phenol

ABSTRACT

This invention relates to the purification of phenol produced by the decomposition of cumene hydroperoxide by heating the phenol with a polyamine compound to remove carbonyl-bearing impurities and then acidifying the phenol to give a product which remains color stable on aging. After the addition of the polyamine compound, the phenol is distilled free of the polyamine compound and the carbonyl-bearing impurities. This distillation can be carried out either before or after the acid is added.

United States Patent Cheema et a1.

[is] 3,692,845 51 Sept. 19,1972

[54] PURIFICATION OF PHENOL [72] Inventors: Zafarullah K. Cheema, Morristown; Pasquale J. Apice, Cresskill; Edwin D. Little, Convent Station, all of [73] Assignee: Allied Chemical Corporation, New

York,N.Y.

[22] Filed: March 12, 1969 [21] Appl. No.: 806,693

Related US. Application Data [63] Continuation-impart of Ser. No. 734,219, June 4, 1968, abandoned.

[52] US. Cl. ..260/621 A, 260/621 C [51] Int. Cl. ..C07c 37/24, C070 37/08 [58] Field of Search ..260/567.5, 621 A, 621 C [56] References Cited UNITED STATES PATENTS 1,942,838 1/1934 Semon ..260/567.5 X 2,490,670 12/1949 Cislak et al. ..260/621 A 3,285,973 11/1966 Arai et a1 ..260/621 A OTHER PUBLICATIONS Layer, Chem Reviews" Vol. 63', pp. 489- 494 (1963) Primary ExaminerLeon Zitver Assistant Examiner-Norman Morgenstem Attorney-Patrick L. Henry and Gerhard l-l. Fuchs [57] ABSTRACT SClaims, No Drawings PURIFICATION OF PHENOL CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of our copending application Ser. No. 734,219, filed June 4, 1968, Purification of Phenol", now abandoned.

PURIFICATION OF PHENOL The production of phenol by the oxidation of cumene and the decomposition of the resulting hydroperoxide in the presence of an acidic catalyst is well known in the art. The decomposition product contains phenol and acetone as the principal products along with minor amounts of various side products. By fractional distillation, phenol can be obtained which is sufficiently pure for many uses. However, such phenol is unsatisfactory for certain purposes and, in particular, when chlorinated or sulfonated with sulfuric acid the phenol discolors and becomes red. Additionally, such phenol generally discolors on aging becoming yellow or pink.

The above-described discoloration on chlorination and sulfonation results from the presence of certain carbonyl-bearing impurities which are not separated by ordinary fractional distillation. These ketonic impurities are generally present in amounts exceeding 300 ppm and include primarily mesityl oxide, acetol and acetophenone.

In accordance with the present invention, it has been discovered that if phenol of the above type containing carbonyl-bearing impurities is contacted with polyamine, an interaction takes place with the ketonic impurities following which it is possible to distill the phenol free from both the polyamine compounds and the ketonic impurities. Phenol thus obtained is substantially free of ketonic impurities and exhibits markedly less discoloration when chlorinated or sulfonated. However, the polyamine treated phenol still discolors on standing and in fact color stability with aging appears to be lessened.

As another aspect of the present invention, it has been discovered that color stability with aging can be imparted if after treatment with a polyamine, the phenol is further treated with an acid. This treatment can be carried out either before or after the phenol is distilled free of the ketonic impurities.

A wide variety of polyamine compounds can be employed in the present invention and any polyamine can be used in which the amino groups are primary or secondary and in which no substituents are present which interfere with the reaction. Suitable polyamines include compounds of the formula wherein n is an integer from to 4, preferably 0 or 1, and most preferably 0, R R and R are independently selected from the group consisting of hydrogen; alkyl, preferably one to carbon atoms; aryl, preferably of six to 10 carbon atoms; cycloalkyl, preferably of four to 10 carbon atoms; aralkyl, preferably of seven to carbon atoms and alkaryl, preferably of seven to 20 carbon atoms, and R, which may be the same or different in different groups, is a member selected from the group consisting of alkyl-ene, preferably of one to 40 carbon atoms; arylene, preferably of six to 10 carbon atoms; alkylenarylene, preferably of seven to 20 carbon atoms; dialkylenearylene, preferably of seven to 20 carbon atoms; cycloalkylene, preferably of four to 10 carbon atoms; dialkylenecycloalkylene, preferably of six to 20 carbon atoms; nitrogen containing heterocyclic groups of five to six carbon atoms and the lower alkyl substituted, hydroxy substituted and carboxyl substituted derivatives of the above listed radicals. R. R, and R are preferably all hydrogen, and R is preferably alkylene or arylene, including lower alkyl, hydroxy or carboxyl substituted derivatives thereof. The alkyl and alkylene groups in these polyamine compounds may be straightchain, branched-chain or cyclic. These polyamines may be used in the form of a single compound, as a mixture of isomers, or as a mixture of polyamines containing from two to six amino nitrogen atoms in the molecule. Illustrative of suitable polyamines are: ortho, meta and para-xylylenediamine; ortho, meta and paratolylene .diamine; hexamethylene diamine; ortho, meta and paraphenylenediamine; 4,5-diamino-xylene; 3,5- diaminobenzoic acid; 3,4-diaminobenzoic acid; 2,6- diaminopyridine; 1,5-diaminonaphthalene; l ,2- diaminonaphthline; 1,5-diaminopentane; l,4-cyclohexanebis (methylamine); N-(3-aminopropyl)cyclohexylamine; N-phenylethylenediamine; 1,3-diamino-2- hydroxypropane; diethylene triamine; di-n-propylene triamine; di-i-butylene triamine; di-n-hexylene triamine, triethylene tetramine; tri-i-propylene tetramine; tri-n-hexylene tetramine; 4 -(2-aminoethyl)- diethylene triamine; tetraethylene pentamine; tetra-npropylene pentamine, tetra-n-butylene pentamine; pentaethylene hexamine; and amines of the formulas H N-RNH where R is an aliphatic hydrocarbon chain of 36 carbon atoms.

The polyamine interacts with or binds the carbonylbearing impurities in such a manner that phenol free of the carbonyl-bearing impurities can be recovered by distillation. The amount of polyamine compound required is, to some extent, dependent upon the concentration of carbonyl-bearing impurities present in the phenol. In general, the amount of polyamine used. is about 0.0 1-2.0 percent; preferably about 003-1 .0 percent based on the weight of the phenol.

The exact temperature at which the phenol is treated with the polyamine compound is not critical. Generally, the treatment is carried out at a temperature of 40220C. and preferably 60-200C. The time of the treatment should be long enough to permit the desired reaction to take place. In general, substantial reaction can be obtained in one minute with a minimum time of about five minutes being preferred.

As previously stated, the acid treatment which follows the addition of polyamine compound can be carried out either before or after the phenol is distilled free of the ketonic impurities. If the acid or acid anhydride is added before the distillation, about 05-10 mols of acid, preferably about two to six mols of acid should be added for each mo] of polyamine compound present. The acid should be permitted to react in the system for at least one minute, preferably at least five minutes before the distillation. Preferably, the reaction of the acid in the polyamine-treated phenol system is carried out at a temperature of about 40200 C. If the acid is added after the distillation, the amount of acid or acid anhydride employed should be about 0.0050.4 percent, preferably 0.0l0.2 percent based on the weight of the phenol.

A wide variety of acids or acid anhydride can be used, the only requirement being that no substituents be present that produce unwanted side reactions. Suitable acids include mineral acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, etc, organic acids such as phthalic acid, fumaric acid, ptoluene-sulfonic acid, etc. and acid anhydrides such as P S0 phthalic anhydride; l,4,5,6,7,7-hexachlorocicyclo[2.2.1 ]-5-heptene-2 ,3-dicarboxylic anhydride, tetrachlorophthalic anhydride, etc.

The distillationwhereby the phenol is freed from the ketonic impurities can be carried out at atmospheric pressure, reduced pressure or super-atmospheric pressure. preferably, distillation is carried out at atmospheric pressure or reduced pressure at a temperature of 80-182 C. depending upon the pressure in the system.

The following examples are given to further illustrate the invention and to set forth the best modes contemplated by us of carrying out the invention, but it is to be understood that the invention is not to be limited by the details described therein. In the examples the following procedures were used for the sulfonation and chlorination color tests.

H SO Color Test:

4.0 g. of the phenol (at about 50-60 C.) to be tested is placed in a sulfonation vessel and 0.4 i 0.01 g. of cone. H SO is added. The mixture is heated in an oil bath with stirring to 150 C. and held at that temperature for five minutes. The sulfonated phenol is then allowed to cool (about one min.) and then transferred to a 1 cm. cell and analyzed by a recording spectrophotometer. The maximum absorption (O.D.) at about 496 m.u. is noted for test purposes. Distilled water is used as a reference.

C1 Color Test:

12.0 g. of the phenol to be tested is placed in a chlorination vessel fitted with a gas inlet tube extending to the bottom of the vessel. The bottom of the inlet tube is constructed of fritted glass to allow fine dispersion of chlorine as it enters the liquid sample is reweighed to confirm 10 percent chlorination and then transferred to a 1 cm. cell for analysis by a recording spectrophotometer. The absorption maximum (O.D.) at about 488 to 496 mu. is noted for test purposes. Distilled water is used as a reference.

In these color tests, the higher the absorption value (O.D.) the more discolored the product. The phenol starting materials used in the examples were produced in accordance with well-known procedures by oxidizing cumene to the hydroperoxide, cleaving the hydroperoxide in the presence of an acidic catalyst and recovering phenol by fractional distillation.

EXAMPLE I The phenol starting material contained a total of 868 ppm of impurities of which 683 ppm were ketonic (mainly mesityl oxide, acetol and acetophenone). 240 grams of the phenol and 0.24 grams of m-xylylenediamine (MXDA) were heated for about 15 minutes at -60 C. and distilled at atmospheric pressure. An 81 percent heart out was collected and part of it was treated with 0.15 percent by weight of Phosphoric Acid at C. until a homogeneous solution was obtained. The pH was less than 2.0 at 55 C. Untreated phenol, phenol treated with MXDA only, and phenol treated with MXDA and phosphoric acid were analyzed and tested for color stability. The results are as follows:

Un- MXDA- treated MXDA H 1 0 Phenol treated treated Impurities (ppm) 868 321 234 Ketonic impurities (ppm) 683 46 32 l-l,SO Test (O.D.) 1.7 0.22 0.26 CI, Test (O.D.) 1.3 0.35 0.31 Color Stability at 60C. Yellow Pink in white in 11 days 2 hrs.

EXAMPLE 2 A quantity of the same phenol starting material as used in Example 1 was treated with 0.1 percent metaxylylene-diamine (MXDA) based on phenol weight for 15 minutes. Aliquots were then acidified with varied amounts of H PO These aliquots plus a sample of the phenol treated with MXDA only were distilled at atmospheric pressure and the heart cuts (60-65 percent) were analyzed for quality and color stability. The results are as follows:

Impurities pH H2804 012 PH before test test after .p.m.) Color-stability Run dist. O.D. O.D. dist Total Ketones* at 60 C.

1. Untreated phenol 1. 7 1. 3 868 683 Turns yellow. 2. MXDA treated 6. O-6. 6 0. 4 0. 4 5. 4 186 08 Pink in few hours. 3. With IIJPO-l, 0.16% 3. 8 0. 5 0. 5 5. 0 246 132 Do. 4. With H PO4, 0.20% 2. O 0. G 0. 6 4. 0 256 135 Lt. pink. 5. With 11 1304, 0.40% 1. 0 0. 7 0. 5 i. 7 219 135 White, 21 days.

*Ketones analyses based on mesityl oxide, acetol and ncetoplieuone content. NOTE.- Runs 3, 4, and 5 had MXlgA/lhPO; mole-ratios of 1/2.2, 1/2.8 and 1/5.6, respectively.

phenol. The vessel is placed in an oil bath and the sample brought to C. Chlorine gas is introduced into the phenol at a controlled rate over five mins. whereby 1.2 g. chlorine is added. The

EXAMPLE 3 The phenol starting material contained 953 ppm of impurities and had the following color characteristicsz 5 6 C12 test 13 Phthalic Anhydride 1/2 0.3 0.5 197 white 6 so D l (0.22%) days 30 32 1 test -)h l d Pgtzhie lxi'c'Anhydride 1/2 0.5 0.7 211 white 3 grams 0 e p eno an 0.15 grams of meta-xyr f lylene-diamine (MXDA) were mixed together and 96% (033% c m 0'3 78 "352 heated at 182 C. Concentrated H 80 was added to 5 ComroLumrealed L3 043 y o give a MXDA/H SQ, mole ratio of 1; 1. The charge was immediately distilled at 182 C. and a 67 percent heart cut collected. The product was analyzed for impurities d ed f color i h h following results: aI84$1.6.7.7-hexachlorobicyclol2.2. l ]-S-heptene-2,3-dicarboxylic any n e. 10 78 ppm of impurities Cl, test (O.D.) 0.3 H 80. test (O.D.) 0.7 and color stable after nine days of storage at 60 C.

EXAMPLE 6 EXAMPLE 4 A sample of the phenol starting material used in Ex- 500 grams of the same phenol as used in Example 5 ample l was treated with 0.1 percent MXDA (based on were admixed with 0.5 grams of m-xylylenediamine phenol weight) at 60 C. for about 15 minutes and then (MXDA) and the mixture was heated at 140 C. for l distilled at 180 C. The heart cut (64 percent) was hour. The mixture was divided into samples and difseparated into 4 equal parts and varying amounts of ferent amounts of phthalic anhydride were added l-l PO (1 percent solution in high purity phenol) were thereto. The samples were heated at 140 C. for 1 hour added to each to yield different levels of acidity. These and then the phenol was distilled at l l0-l 20 C. under were then analyzed for quality and color-stability. The reduced pressure and heart cuts collected. The results were as follows: products were analyzed and the color stability tested.

H2So4 Color Run test 012 test Impurities N0. pII O.D. O.D. (p.p.m.) On acidification 0n standing 1 Untreated phenol .7 .3 868 2 MXDA treated, not acidified 0.0 0.4 0.3 140 Pink. 3 MXDA treated plus 0.007% llalOi 3.1 0.4 0.3 215 Yellow-pink Oil-white. 4. MXDA treated plus 0.024% li3lO1. 2.4 0.2 0.3 155 Si. yellow-pi11k White. 5. MXDA treated plus 0.12% II3P04 1.0 0. 3 0.2 157 V it. yellow.. Do. 0 MXDA treated plus 0.20% 113104 0. 7 0. 6 0. L. 105 l0 Do.

EXAMPLE 5 v The results are g1ven 1n the followmg table:

The starting phenol employed contained 1043 ppm of impurities. 1.2 kilograms of this phenol and 1.2 MXDA/ grams of meta-xylylenediamine (MXDA) were heated PAA r together at l65l70 C. for one hour. Aliquots were 40 g g Fumes (ppm) 60 C. then treated with var1ous acids and ac1d anhydrldes at temperatures in the range of l20-l70 C. for times ranging from one-half to 24 hours. The purified phenol ifi' 8:53 8:22 333 gg-3" was then recovered (7080 percent heart cuts) by V5.5 0.31 0.50 229 white distillation at 100-1 10 millimeters pressure. The results U/nueated M7 290 are given in the following Table with the concentration 1.8 1.3 1043 yellow-it. amber of each acid or anhydride in percent of the weight of the phenol being indicated in parenthesis after the name of each compound:

EXAMPLE 7 MXDA lm- Acid H2504 Cl puri Color A sample of the same phenol as used as a starting Acid Mole. Test test ties 8mm, matenal in Example 5 was admlxed w1th 0.1 percent by Anhydride Ratio 0.0. O.D- (pp 3 weight of meta-xylylenediamine (MXDA). The mixture was divided into a number of portions which were heated for the times and at the temperatures indicated :gif' H25 O3 187 white 26 in the Table below. After treatment with MXDA, 0. l h days phthalic anhydride (PAA) was added (MX- po uenesu p onic DA/PAA=% mol ratio) and the indicated temperature 233 Us 1;; held for an additional h hour. The phenol samples 35% r1,1 o. o.43% V6 0.6 0.5 309 white 4 were distilled at l00-l 15 C. under reduced pressure eye 00% HSPOAOAfi) H6 0'5 223 white and heart cuts collected. The products were analyzed days and the1r color stability determlned. The results are 1nz r (050%) l/7 269 gz dicated in the following table: HI-IT" Anhydride" l 65 0.54%) 1/2 0.3 0.6 260 white 11 I days Temp. Time Test Test purities Color Stability Tetrachlorophthalic l l/2 0.4 0.6 231 white l0 (C.) (hr- Q D Q D (ppm) at T- (0.45%) Anhydride days Fumaric Acid 0.171 1/2 0.4 0.4 219 white 4 so 1 0.83 0.74 209 white 12 days days so 5 0.49 0.53 257 v s1. yellow 12 Reaction Time, (Mins.) at 165C.

Mesityl Oxide 91 82 81 58 37 Acetol 718 43 0 0 0 Acetophenone 148 N.C. 123 85 88 Total Impurities 1133 448 356 288 233 Several other impurities are present in low ppm.

This experiment shows that short reaction times can be used to reduce major carbonyl impurity-acetol.

EXAMPLE 9 To show the effect of m-xylylenediamine (MXDA) concentration, samples of three phenols were treated with various amounts of MXDA. The first phenol contained 530 ppm of total impurities including 348 ppm ketonic impurities. The second phenol contained 1,036 ppm total impurities including 903 ppm of ketonic impurities. The third phenol contained 1695 ppm of total impurities including 1255 ppm of ketonic impurities.

The results are shown in the following tables:

TABLE A impurities 11,80 C1, Run MXDA Temp. Time Test Test Total Ketonic No. (76) ("C.) (hrs.) O.D. O.D- (PP (ppm) (un- 1 0.00 treat- 2.4 1.4 530 348 TABLE B Impurities H,SO C1 Run MXDA Temp. Time Test Test Total Ketonic No. (11) (C.) (hrs.) O.D. O.D (ppm) (ppm) (unl 0.00 treat- 1.6 1.5 1036 903 TABLE C Impurities H,SO C1,

Run MXDA Temp. Time Test Test Total Ketonic No. :0.) (hrs.) 0.0. 0D. (ppm) (PPm) um I 0.0 treat- 1.2 1.4 1695 1255 EXAMPLE 10 This example shows the effect of a mixed toluenediamine (MTD) in removing the ketonic impurities of phenol. The starting phenol contained 1 133 ppm of impurities of which 963 ppm were ketonic impurities. Aliquots of the phenol were treated with 0.1 percent by weight (based on the phenol weight) of a mixture containing 78 percent of 2,4-diamino-toluene, 19 percent of 2,6-diaminotoluene and 3 percent of 2,3- and 2,5- diaminotoluene and the samples were reacted for one hour at 165 C. Phthalic anhydride was then added in amounts to give MTD/PAA mole ratios of H05, 1/1 and H3. Heating was maintained at 165C. for /4 hour and percent heart cuts were collected under reduced pressure and 165 C. Analysis of the products gave the following results:

MTD/PAA H 50, Cl, lm- Color Mole- Test Test purities stability Run No. ratio CD. CD. (PP at 60C. 1 H05 0.4 0.6 176 wht. 7 days 2 1/1 0.4 0.6 wht. 10 days 3 H3 0.8 0.5 wht. 7 days The above process was repeated using a sample having a MTD/PAA mole ratio of 1:3 except that after adding the phthalic anhydride the reaction mixture was heated at 165 C. for 20 hours. The product obtained contained 99 ppm of total impurities, less than 5 ppm ketonic impurities and was still white after 8 days storage.

EXAMPLE 11 This example demonstrates the effectiveness of a number of polyamines in removing color-forming impurities. The phenol used was the same as that employed in Example 10. The polyamines were tested by adding 0.1 gram of each to grams aliquots of the phenol and then heating the mixture to 182 C. for one hour. After distillation at atmospheric pressure, a 75 percent heart out was obtained and analyzed. The results are as follows:

Phenol Test Cl, purities Treated With (O.D.) (O.D.) (ppm) No Treatment 1.8 1.5 1133 2.4-Toluenediamine 0.3 0.6 230 3,4-Toluenediamine 0.6 0.7 457 2,5-Toluenediamine 0.4 0.6 334 2,6-To1uenediamine 0.3 0.8 o-phenylenediamine 0.4 0.5 m-phenylenediamine 0.2 0.9 249 4,5-Diamino-O-xylene 0.4 0.8 3,5-Diaminobenzoic Acid 0.6 0.6 3,4-Diaminobenzoic Acid 0.5 0.7 2,6-Diaminopyridine 0.8 0.7 1,5-Diarninonaphthalene 0.2 0.7 p-phenylenediamine 0.9 337 1,2-Diaminonaphthalene 0.8 0.8

EXAMPLE 12 Aliquots of phenol were treated with hexamethylenediamine (l-lMDA) at the concentrations indicated below at 180? C. (based on the phenol weight) for 1 hour and then distilled at 182 C. A 90 percent heart cut was taken as the product and analyzed. The results are indicated in the following table:

Test Test purities HMDA (O.D.) (O.D.) (ppm) Remarks 0.00 1.8 1.5 1 133 963 ppm total ketones 0.01 1.5 0.9 635 478 ppm total ketones' 0.02 1.1 0.7 320 218 ppm total ketones' 0.03 0.7 0.7 185 79 ppm total ketones' 0.04 0.4 0.5 174 35 ppm total ketones' 0.07 0.2 0.5 95 ppm total ketones" consistsmainly of mesityl oxide. acetol, aeetophenone.

All of the above distillates developed a light pink color upon aging a few hours at 60 C.

EXAMPLE 13 The following example shows the effect of different concentrations of phthalic anhydride (PAA) on color stability after impure phenol has been treated with hexamethylenediamine (HMDA). Aliquots of the same phenol as used as starting material in Example 10 were treated at 165 C. for 1 hour with 0.1 percent HMDA, based on the phenol weight, and then the amounts of PAA shown below were added. The mixtures were then heated at 165 C. for hours and distilled. The distillates were analyzed and tested for color stability with the following results:

HMDA/ PAA H 80 Cl lmmole- Test Test purities Color Stability ratio (O.D (O.D.) (ppm) at 60C.

H05 0 2 0.3 87 Pink in few hrs.

1/1 0 3 0.4 124 Pink after days 1/2 0 6 0.4 261 White 1/3 0 4 0.6 203 White 2 weeks EXAMPLE 14 This example illustrates treating phenol with a diamine at a temperature above the atmospheric boiling point of phenol. A sample of phenol starting material as described in Example 10 was treated with 0.1 percent of HMDA, based on the phenol weight, at 220 C. (about 2 atmospheres pressure) for 6 hours and then distilled at atmospheric pressure. A 90 percent heart out was collected and analyzed with the following results:

H 80 Test (O.D.) 0.07

C1 Test (O.D.) 0.05 and total impurities 136 ppm.

EXAMPLE 15 This example illustrates the use of a combination of polyamines. A phenol starting material as described in Example 1 was admixed with 0.1 percent based on the phenol weight of a mixed diamine containing 60 percent by weight of the mixed toluene diamine described EXAMPLE 16 The following example illustrates the use of a product containing mixed aliphatic diamines (MAD). The amines consisted of 90% of the compound l-l N- 2)?- (HE-(CHEMCH:

and 10% of the compound xuqtil sf hendlweie'iieateFwinibiMZiid 6.55

weight percent of the above mixed product for two hours at 182 C. and then distilled. Analyses of the distillates (71 percent center cut) are shown below:

H,SO [m- Test Cl, Test purities Run No. (O.D.) (O.D.) (ppm) 1 Untreated Phenol 1.6 1.5 1036 2 0.25% MAD 0.7 0.4 131 3 0.04% MAD 1.4 0.9 553 EXAMPLE 17 This example illustrates the reduction of color-forming impurities in phenol by the use of a diamine dimer having the formula H NRNH where R is an aliphatic hydrocarbon chain at 36 carbon atoms. The phenol was treated with the diamine dimer at concentrations of 0.05 and 0.10 percent based on the phenol weight for 1 hour at 182 C. and then distilled. A 78 percent center cut was collected and analyzed. The results are shown below:

H SO. lm- Test Cl, Test purities Run No. (O.D.) (O.D.) (ppm) 1 Untreated Phenol 1.8 1.5 1 133 2 0.05 diamine dimer 1.0 0.6 3 0.1% diamine dimer 0.4 0.6

EXAMPLE 18 The procedure of Example 17 was repeated employing as polyamine a 0.1 percent by weight concentration of 1,5-diamino-pentane. The results are given in the following table:

H 80 Im- Test Cl, Test purities Run No. (O.D.) (O.D.) (ppm) 1 Untreated Phenol 1.8 1.5 1 133 2 0.1% 1,5-Diamino- 0.3 0.3

pentane EXAMPLE 19 A starting phenol containing 1.133 ppm of impurities, of which 967 ppm were ketonic impurities consisting mainly of mesityl oxide (91 ppm), acetol (718 ppm, and acetophenone (148 ppm) and having the following sulfonation and chlorination characteristics:

H SO Test (O.D.) 1.8

Cl Test (O.D.) 1.5 was treated with 0.1 percent based on the phenol weight of a mixed polyamine consisting of di-hexamethylene triamine (about 47 percent) and higher homologues thereof of the formula EXAMPLE 20 The following example illustrates the effect of additional polyamines in reducing the color-forming impurities of phenol. The starting phenol contained 1133 ppm of impurities and had the following sulfonation and chlorination test characteristics:

H2804 Test 1 C1 Test (O.D.) 1.5 This phenol was mixed with 0.1 percent based on the phenol weight of the polyamines listed below and heated for one hour at 182 C. After distillation, the product was analyzed. The sulfonation, chlorination and impurity (ppm) values are shown in parentheses.

H Test (O.D.) 1.2

Cl, Test (O.D.) 1.5

Another phenol sample having a total impurity content of 1089 ppm,

H 80 Test (O.D.) 1.8

Cl Test (O.D.) 1.2 was subjected to steam distillation with up to 16 percent water present. An percent center cut was collected and analyzed as follows:

944 ppm of impurities l-l SO Test (O.D.) 1.2

Cl Test (O.D.) 1.0

To demonstrate that acids and acid anhydride treatment does not remove impurities, phenol was treated with H PO in an amount equal to 0.3 percent of the phenol weight and phthalic anhydride in an amount equal to 0.22 percent of the phenol weight and distilled at atmospheric pressure. The 70 percent center cuts were analyzed as follows:

Cl, Test It will be apparent that many modifications and variations can be effected without departing from the scope of the novel concepts of the present invention and the illustrative details disclosed are not to be construed as imposing undue limitations on the invention.

We claim:

1. A process for the purification of phenol produced by the decomposition of cumene hydroperoxide and containing carbonyl-bearing impurities which comprises contacting the phenol at a temperature of about 40 to 220 C. for at least one minute with 0.01 to 2.0 percent by weight of a polyamine compound of the formula 1,4-cyclohexanebis (rncthylamine) H NCHz S CH NH1 H N-(3-aminopropyl) cyclohexylamine S N(CHz)3-NH H N-phenylethylenediamine N(CH2)2NH n1 1, S-diamino-2-hydroxypropane HZNOHQCHCHZNHZ Chlorl- Sulfo- Im punation nation rities wherein n is an integer of from 0 to 4, R R and R are independently selected from the group consisting of hydrogen, alkyl, aryl, cycloalkyl, aralkyl and alkaryl, and R, which may be the same or difierent in different groups, is a member selected from the group consisting of alkylene, arylene, alkylene-arylene, dialkylenearylene, cycloalkylene, dialkylene cycloalkylene, and unsubstituted nitrogen-containing heterocyclic groups of five to six carbon atoms, adding 0.5 to mols of an acid or acid anhydride per mol of polyamine compound and distilling said phenol free of said polyamine compound and said carbonyl bearing impurities.

2. A process as claimed in claim 1 wherein said phenol is contacted with said polyamine at a temperature of about 60 C. to 200 C. for at least five minutes prior to the addition of said acid.

3. A process as claimed in claim 2 wherein the amount of polyamine compound used is equal to 0.03 to 1.0 percent of the weight of the phenol.

4. A process as claimed in claim 2 wherein about 2 to 6 mols of acid or acid anhydride is added per mol of polyamine compound.

5. A process as claimed in claim 4 wherein after the addition of said acid the reaction mixture is heated at a temperature of 40 to 200 C. for at least one minute prior to said distillation step.

6. A process as claimed in claim 1 wherein in the polyamine compound of the formula H R: H Rr-I I(R-I I)n-R1 IR1 wherein n is grea terthan 2, and the acid anhydride is phthalic acid anhydride. 

2. A process as claimed in claim 1 wherein said phenol is contacted with said polyamine at a temperature of about 60* C. to 200* C. for at least five minutes prior to the addition of said acid.
 3. A process as claimed in claim 2 wherein the amount of polyamine compound used is equal to 0.03 to 1.0 percent of the weight of the phenol.
 4. A process as claimed in claim 2 wherein about 2 to 6 mols of acid or acid anhydride is added per mol of polyamine compound.
 5. A process as claimed in claim 4 wherein after the addition of said acid the reaction mixture is heated at a temperature of 40* to 200* C. for at least one minute prior to said distillation step.
 6. A process as claimed in claim 1 wherein in the polyamine compound of the formula R1, R2 and R3 are all hydrogen, and R is selected from the group consisting of straight chain alkylene, branched chain alkylene, and arylene.
 7. A process as claimed in claim 5 wherein the polyamine compound is hexamethylene diamine and the acid or acid anhydride is phthalic acid or phthalic acid anhydride.
 8. A process as claimed in claim 5 wherein the polyamine compound consists of di-hexamethylene triamine and hIgher homologues thereof of the formula NH2((CH2)6NH)nH wherein n is greater than 2, and the acid anhydride is phthalic acid anhydride. 